27 research outputs found
MATERNAL MORTALITY IN AFGHANISTAN. CURRENT STATE OF THE PROBLEM
The article is devoted to the issue of maternal mortality in Afghanistan. What results did this country achieve after setting the millennium goals in 2000? The causes of maternal mortality have been analyzed. A survey has been carried out on the demographic and geographical differences in maternal mortality in different regions of the world and possible ways of overcoming the current causes of mortality. Conclusion. The key and effective measures to prevent maternal mortality in Afghanistan are access to: a family planning center, the possibility of medical abortion, emergency obstetric care
Neural network interpretation techniques for analysis of histological images of breast abnormalities
Background. Neural networks are actively used in digital pathology to analyze histological images and support medical decision-making. A common approach is to solve the classification problem, where only class labels are the only model responses. However, one should understand which areas of the image have the most significant impact on the model's response. Machine learning interpretation techniques help solve this problem.
Aim. To study the consistency of different methods of neural network interpretation when classifying histological images of the breast and to obtain an expert assessment of the results of the evaluated methods.
Materials and methods. We performed a preliminary analysis and pre-processing of the existing data set used to train pre-selected neural network models. The existing methods of visualizing the areas of attention of trained models on easy-to-understand data were applied, followed by verification of their correct use. The same neural network models were trained on histological data, and the selected interpretation methods were used to systematize histological images, followed by the evaluation of the results consistency and an expert assessment of the results.
Results. In this paper, several methods of interpreting machine learning are studied using two different neural network architectures and a set of histological images of breast abnormalities. Results of ResNet18 and ViT-B-16 models training on a set of histological images on the test sample: accuracy metric 0.89 and 0.89, ROC_AUC metric 0.99 and 0.96, respectively. The results were also evaluated by an expert using the Label Studio tool. For each pair of images, the expert was asked to select the most appropriate answer ("Yes" or "No") to the question: "The highlighted areas generally correspond to the Malignant class." The "Yes" response rate for the ResNet_Malignant category was 0.56; for ViT_Malignant, it was 1.0.
Conclusion. Interpretability experiments were conducted with two different architectures: the ResNet18 convolutional network and the ViT-B-16 attention-enhanced network. The results of the trained models were visualized using the GradCAM and Attention Rollout methods, respectively. First, experiments were conducted on a simple-to-interpret dataset to ensure they were used correctly. The methods are then applied to the set of histological images. In easy-to-understand images (cat images), the convolutional network is more consistent with human perception; on the contrary, in histological images of breast cancer, ViT-B-16 provided results much more similar to the expert's perception
Pre-exposure prophylaxis of new COVID-19 coronavirus infection with tixagevimab/cilgavimab in adult Moscow patients with primary immunodeficiencies
Background. Primary immunodeficiencies (PIDs), now known as inborn errors of immunity, are a group of inherited diseases caused by defects in the genes that control the immune response. Patients with PIDs have risks of developing a severe course and/or death in COVID-19. Passive immunization with long-acting monoclonal antibodies (MABs) to SARS-CoV-2 should be considered as pre-exposure prophylaxis in patients with PIDs. Tixagevimab/cilgavimab is a combination of MABs that bind to the SARS-CoV-2 spike protein.
Aim. To evaluate the efficacy and safety of pre-exposure prophylaxis of new SARS-CoV-2 infection in PIDs with the combination of tixagevimab/cilgavimab.
Materials and methods. Forty eight patients diagnosed with PIDs were included in the study. Median follow-up after drug administration was 174 days. The total number of confirmed coronavirus infections in patients with PIDs as well as 6 months before and after administration of MAT were assessed.
Results. In the analyzed cohort, the overall incidence of COVID-19 from pandemic onset to MABs administration was 75% (36/48), with 31% (11/36) of over-infected patients having had the infection more than once. The incidence of COVID-19 immediately 6 months before the introduction of tixagevimab/cilgavimab was 40%. All patients who had COVID-19 after pre-exposure prophylaxis had a mild infection. The incidence of COVID-19 6 months after tixagevimab/cilgavimab administration significantly decreased compared to the incidence 6 months before administration (7 and 40%, respectively; p0.001).
Conclusion. The use of tixagevimab/cilgavimab in patients with PIDs is effective as pre-exposure prophylaxis and reduces the risk of severe COVID-19
Modeling of GERDA Phase II data
The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground
laboratory (LNGS) of INFN is searching for neutrinoless double-beta
() decay of Ge. The technological challenge of GERDA is
to operate in a "background-free" regime in the region of interest (ROI) after
analysis cuts for the full 100kgyr target exposure of the
experiment. A careful modeling and decomposition of the full-range energy
spectrum is essential to predict the shape and composition of events in the ROI
around for the search, to extract a precise
measurement of the half-life of the double-beta decay mode with neutrinos
() and in order to identify the location of residual
impurities. The latter will permit future experiments to build strategies in
order to further lower the background and achieve even better sensitivities. In
this article the background decomposition prior to analysis cuts is presented
for GERDA Phase II. The background model fit yields a flat spectrum in the ROI
with a background index (BI) of cts/(kgkeVyr) for the enriched BEGe data set and
cts/(kgkeVyr) for the
enriched coaxial data set. These values are similar to the one of Gerda Phase I
despite a much larger number of detectors and hence radioactive hardware
components
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Modeling of GERDA Phase II data
The GERmanium Detector Array (Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta (0νββ) decay of 76Ge. The technological challenge of Gerda is to operate in a “background-free” regime in the region of interest (ROI) after analysis cuts for the full 100 kg·yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around Qββ for the 0νββ search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos (2νββ) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for Gerda Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of 16.04+0.78−0.85⋅10−3 cts/(keV·kg·yr) for the enriched BEGe data set and 14.68+0.47−0.52⋅10−3 cts/(keV·kg·yr) for the enriched coaxial data set. These values are similar to the one of Phase I despite a much larger number of detectors and hence radioactive hardware components
Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021
IntroductionThe J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI.ResultsIn this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients’ data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174).Conclusions1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries
Influence of <i>Picea Abies</i> Logs on the Distribution of Vascular Plants in Old-Growth Spruce Forests
The deadwood contributes to an increase in soil heterogeneity due to the changing the microrelief (by the formation of windthrow-soil complexes), as well as changes in physical and chemical characteristics of decaying wood directly during xylolysis. We hypothesized that fallen logs as an element of microrelief influence the species composition and cover structure of vascular plants. We studied the influence of Picea abies (L.) Karst fallen logs of moderate and advanced decay stages on the horizontal distribution and heterogeneity of vascular plant cover in different microsite types (small boreal grass type, blueberry type, small boreal grass-blueberry type, herbs, and blueberry type) in old-growth middle taiga spruce forest in the Kivach State Nature Reserve (Republic of Karelia, Russia). The fallen deadwood acts as a factor of heterogeneity, causing reversible changes in the homogeneity of the original plant cover. The decaying logs influence the horizontal distribution of small herbs by changing the occurrence and density of shoots of Oxalis acetosella L., Maianthemum bifolium (L.) F.W. Schmidt, Vaccinium myrtillus L., and Vaccinium vitis-idaea L., as well as the occurrence of Luzula pilosa (L.) Willd. and Calamagrostis arundinacea (L.) Roth. Its impact on the heterogeneity parameters can be traced up to 20 cm from the log. The differences in vascular plant cover between fallen logs and the surrounding forest floor depend on the soil conditions of the microsite. The heterogeneity of conditions created by the logs smoothed out with increasing decay class, resulting in decreasing differences in the heterogeneity parameters of vascular plant cover between deadwood and forest floor. The changes in the homogeneity of the initial vascular plant cover by deadwood and the gradual smoothing of heterogeneity between the logs and the forest floor in rich and poor conditions have different, mainly opposite, trends. Finally, the structure of the vegetation cover reaches a state that is typical of particular growth conditions beyond deadwood
Determining the Features of Temperature Influence on the Load-bearing Structure of A Hopper Car with A Composite Cladding When Transporting Pellets to Metallurgical Enterprises
This paper reports the improved load-bearing structure of a hopper car for transporting pellets and hot sinter. In order to increase the strength of the load-bearing structure of a hopper car under the influence of high temperatures from the transported cargo, the use of cladding made of composite material has been proposed. This solution also contributes to a 5 % reduction in the wagon's tare compared to the prototype car.
The dynamic load on the load-bearing structure of a hopper car was determined. This study was carried out for the case where an empty wagon was moving over an irregularity between the rail joints. The calculations showed that the studied dynamics indicators did not exceed the permissible values. At the same time, the ride of a hopper car is rated as "excellent".
The main indicators of the strength of the carrying structure of a hopper car were determined taking into consideration the proposed improvement. That took into account the temperature effect exerted on the load-bearing structure of a hopper car by hot sinter. It was established that the maximum equivalent stresses occur in the zone of interaction of the girder beam with the pivot beam and are about 290 MPa. At the same time, stresses in the cladding of a hopper car are about 200 MPa, which is 12 % lower than those in a regular structure.
Modal analysis was carried out to determine the frequencies and shapes of the natural oscillations of the bearing structure of a hopper car with a composite cladding. The calculation results demonstrated that the first natural frequency exceeds 8 Hz. Therefore, the safety of the wagon is provided.
The coefficient of fatigue resistance of the load-bearing structure of a hopper car was calculated. It was established that its value is almost twice as high as the permissible one. That is, the resistance to fatigue of the supporting structure is provided.
The research reported here could contribute to ensuring the strength of the load-bearing structures of hopper cars, reducing the cost of maintenance, and increasing the efficiency of their operation
Determining the Features of Temperature Influence on the Load-bearing Structure of A Hopper Car with A Composite Cladding When Transporting Pellets to Metallurgical Enterprises
This paper reports the improved load-bearing structure of a hopper car for transporting pellets and hot sinter. In order to increase the strength of the load-bearing structure of a hopper car under the influence of high temperatures from the transported cargo, the use of cladding made of composite material has been proposed. This solution also contributes to a 5 % reduction in the wagon's tare compared to the prototype car.
The dynamic load on the load-bearing structure of a hopper car was determined. This study was carried out for the case where an empty wagon was moving over an irregularity between the rail joints. The calculations showed that the studied dynamics indicators did not exceed the permissible values. At the same time, the ride of a hopper car is rated as "excellent".
The main indicators of the strength of the carrying structure of a hopper car were determined taking into consideration the proposed improvement. That took into account the temperature effect exerted on the load-bearing structure of a hopper car by hot sinter. It was established that the maximum equivalent stresses occur in the zone of interaction of the girder beam with the pivot beam and are about 290 MPa. At the same time, stresses in the cladding of a hopper car are about 200 MPa, which is 12 % lower than those in a regular structure.
Modal analysis was carried out to determine the frequencies and shapes of the natural oscillations of the bearing structure of a hopper car with a composite cladding. The calculation results demonstrated that the first natural frequency exceeds 8 Hz. Therefore, the safety of the wagon is provided.
The coefficient of fatigue resistance of the load-bearing structure of a hopper car was calculated. It was established that its value is almost twice as high as the permissible one. That is, the resistance to fatigue of the supporting structure is provided.
The research reported here could contribute to ensuring the strength of the load-bearing structures of hopper cars, reducing the cost of maintenance, and increasing the efficiency of their operation